im trying to upgrade my sisters computer here, a simple task of adding more ram. Right now its using DDR SDRAM 333 Mhz with a CL of 2.5

is it OK to choose memory with a CL of 2, or a one with a CL of 3?

The CL 2.5 means that it takes 2.5 cycles to access the first bit of memory... so in this instance the lower the CL the faster the memory. If you went with CL3, I'd assume that all modules would have to run at that (slower) speed. If you went with CL2, I'd assume that all modules would run at CL2.5.

http://www.pcworld.com/article/113 [...] ystem.html

hmm cool thanks, i think i'll just get the 3 cuz its cheaper, this computer isnt for OC'ing or anything, just casual computing, stuff like that.

thanks!

You can buy either DDR-333 or DDR-400.